File:Global temperature anomalies between 1994-2008, estimated by NASA’s Goddard Institute for Space Studies (GISTEMP) and the UK Met Office and the University of East Anglia’s Climatic Research Unit (HadCRUT3).gif

English: The following description is based on the cited public-domain source: This image shows a graph of global temperature anomalies between 1994 and 2008, estimated by NASA’s Goddard Institute for Space Studies (GISTEMP) and the UK Met Office and the University of East Anglia’s Climatic Research Unit (HadCRUT3). The consistently higher temperature indicated by GISTEMP is the result of the two groups measuring anomalies from different base periods: GISTEMP values show how much the world has warmed compared to the average from 1951 – 1980 while HadCRUT3 values show the change from the 1961 – 1990 average. Differences in how each group calculates global temperature result in differences in each year’s ranking. HadCRUT3 lists 1998 as the warmest year, followed by 2005 and 2003. GISTEMP shows 2005 as the warmest year, followed by 2007 and 1998.

The graph shows both annual and smoothed anomalies over the time period. Variability in the annual anomalies is discussed in en:Attribution of recent climate change#Internal climate variability and global warming. The smoothed data shows a trend of warming between 1994 and 2008. For the HadCRUT3 dataset, recent years (2004-2008) show a levelling out of the warming trend. However, recent years are among the warmest on record (over the entire instrumental record).